Operating mechanism for slide valves



Dec. 29,1925- A l v v U. S. ALSRUHE -oPERATING MECHANISM FOR SLIDEVALVES Filed Jan. 22, 1925 will..

' r m m m mm vtional type of engine.

Patentedk Dec. 29, 1925.

UNITED STATES is'zs PATENT office."

URBAN S. ALSRUHE, 0F TOW'SON, MARYLAND.

To all whom t may concern.'

Be it known that I, URBAN S. ALsnUHE, a citizen of the United States,residing at Towson, in the county of Baltimore and State of Maryland,have invented an Operating Mechanism for Slide Valves, of whichl thefollowing is a full and complete specification.

My invention is an improvement in slidevalve mechanism for engines usingsteam or compressed air as the motive force, and rclates more especiallyto the means by which the slide-valve is actuated to cooperate with theinlet and outlet ports of the cylinder. In the operation of theconventional type of engine having a cylinder and slide-valve withmechanism for operating the latter comprising connecting rods and a camdevice on a driven shaft the reciprocating motion imparted to theslide-valve admits the Huid pressure gradually into the cylinder withacorresponding exhaust owing to the operation of the usual form of cam,and this interferes to a more or less extent with the effectiveoperation of the power introduced into the cylinder and exhaustedtherefrom in the operation of the piston.

The principal object of my invention is to provide a particular form ofcam device for operating the slide-valve through the intervention of theusual connecting rods, whereby the slide is moved quickly from oneposition to the other for a more effective intake and exhaust of thesteam or fluid pressure so as to insure a more powerful and economicaloperation of the engine.

"Afurther object of my Vinvention ris to provide an operating device forimparting a reciprocating motion to the rods operating theusual form ofslide-valve which may be readily substituted for the ordinary form ofcam ordinarily used, the voperating device in the present instance beingnot only effective `in the operation of the engine but also simpley inconstruction, positive in action, and y.easily applied, r` `K Otheryobjects and advantages of my in- 'vention' will hereinafter appear, andwhat I claim vas new and desire to secure byLetters-Patent ismorespecifically set forthin the appendedclaims., ,v

In the drawings, forming alpart ofpthis specification i Fig. 1 is aside-elevation illustrating the application ofl my invention to aconven- OPEBATING MECHANISM FOR SLIDE VALVES.

Application filed January 22,1925. SerialrNo. 4,124.

Fig. 2 is an enlarged detail view, in side elevation, of the operatingmechanism or cam device comprising my invention.

Fig. 3 is a similar view, with the side plate removed and the yokemember partly in section.

Fig. 4; is a vertical sectional view through the operating mechanism orcam device.

I have illustrated my invention as applied to a conventional type ofengine comprising a cylinder 10 through one end of which the piston-rod11 works and is connected to the driving-arm 12 applying the power bymeans of a slide 13 having a reciprocating movement between guide-rails14 supported by standards 15; the cylinder being provided as usual withya steamvchest k16 in which the ordinary forni of slide-valve (not shown)operates to successively cover and uncover the inlet and exhaust portsleading into the cylinder. This type of engine is also provided with avalve-rod 17 extending through one end of the steam-chest for theoperation of therslide-valve. and as usual this rod is actuated from adriven shaft, as 22, by a connecting-rod 2O and cam device on said shaftwith a slide 18 supported in guide-rails 19 forming part of theconnections. These parts are all common to this type of engine, andtherefore further description of the con-` 8 struction and operation ofthe same is unnecessary, being well understood by those f skilled intheart, and are illustrated herein to show one application of my improvedform of operating mechanism or cam device. Furthermore, it will beunderstood that the application of my improved operating mechanism orcam device, hereinafter particularly described, is not limited in itsapplication to this particular type of engine but may -be used inconnectionv with other v forms` of engines and in other situations whereit is desired toimpart an intermittent reciprocating motion to aconnectingrod, &c.

In carrying out my invention I provide in the first place a metal wheel23 having its periphery concentric to its axisfor shaft on which it ismounted, and attach to the periphery atthe center thereof a singletappet 24: having its' working face beveled, as

shown, to cooperate with shoulders on the the tappet-wheel Vbeing forthe purpose pro- 11 vided internally with an elliptical recess andcentral openings at its sides to receive Laid wheel and its drivingshaft so that the said yoke may have a limited reciprocating motion, thenarrow part of the recess being of approximately the same diameter asthe wheel for a proper bearing` ot the yoke and of course the extent otmovement is determined by the length o1 the elliptical-shapedv recess.1n order to impart an intermittent reciprocating; mot-ion to theyoke-member for a quick movement of the slide-valve, ineontradistinction to the slow ot gradual movement imparted by theordinary form of cam, shoulders 27a 2T are formed in said yoke-member atopposite sides of the narrow part ot the elliptical recess therein, saidshoulders being preferably in the form ot spring-actuated dogs for thepurpose hereinatter explained, and in operation the tappet 24e when thewheel Q3 is turned in either direction passes one oi the shoulders ordogs and engages the other to move the yoke alternately in oppositedirections. To accomplish this the shoulders termed hy thespring-actuated dogs are located at opposite sides oit the transversediameter oiC the elliptical recess, in cavities QS, and are spaced fromsaid diameter respectively so that their tangential movement withrespect to the wheel'permits the tappet to pass the shoulder or dog` atthe limit of n'iovement ot the yoke-member in the same direction as saidtappet, the dog` in this instance forming' a rigid shoulder by bearingagainst the wall of recess 28; for instance, when the tappet-wheel isrotatingin the direction of the arrow Fig. 3 the tappet 24e engages dogs2? successively and moves the yoke-member in opposite directionsalternatel i and in each instance until the tappet passes the dog 27-itbeingl understood that it is the tangential movement of the rigid dogcarried by the yf-'oke-member that allows the tappet to pass said dog.lhen'the direction ot movement or rotation of the driving-shaft andtappeti-wheel is reversed the tappet will then in like manner pass bythe dogs 27a without disturbing the same and engage dogs 27 to impartthe required reciprocating motion to the yoke-member. Although rigidshoulders may be used it is preferable to use the spring-actuatedl dogsto permit the tappet to move one ont the dogs ont of the way and pass onto the other under certain conditions. as for. instance when theyoke-member is by accident or otherwise moved to an intermediateposition when the tappet is on a line with the longitudinal diameter ofthe elliptical recess.v then when the tappet-wheel is rotated the tappetwould trip the first dog and engage the second to move the yoke-membertorna further regular operation of the cam device; that is to say,suppose the tappet to be at the forward part oit the wheel, on a linewith the longitudinal center ot the elliptical recess and the yokemember should be moved to the lett (Fig. a rotation ot' the tappetwheelin the direction ot the arrow would trip dog 27h at the lower part otthe yokeineinber and engage dog QT, and, conversely, a reverse rotationot the tappet-wheel would trip spring-actuated dog 2T at the upper partox'f' the yoke-member and pass on to engage dog- QT". Ot course in theregular operation ot the cam device the Yfriction oi the parts itoperates, as for instance the valve-slide. slide l?, and connecting rods1T and :'30, will hold the yoke member to limit ot movement in bothdirections, but as hercinbefore pointed out a shoulder or member whichwill yield in one direction is desiraole to take care ot an emergencysuch as stated, 'tor it ri gid shoulders were provided the tappetwould.in the case stated, engage the first shouloer and by moving; it towardsthe transverse diameter ot the elliptical recess. or towards theperiphery ot the tappetwhcel, lock the parts. lt will be readily seen,thcre'ore7 that in the regular operation et the cam device one set otdogs only are engaged in successirm, according to the rotation ot theshaft and tappet-wheel, and consequently the tripping ot the dogs takesplace to prevent interlocking ot the parts only.

From the foregoing description ot the construction and operation ot myimproved cam device it will be noted that it provides it'or a quickintermittent reciprocating motion ot the yoke-member and mechanism towhich it is connected, as 'for instance in the operation ot theslide-valve of an engine, and in this instance ot' course the operationof the cam is timed with respect to the operation ot the slide-valve foroperation of the engine, and of course the engine will be provided withthe usual means for controlling its operation, including a governor. ByprovidingY the engine with this form of cam device, for a quickermovement ot the slide-valve the inlet port and exhaust port areuncovered quickly for a more eitective operation ot the piston.

I claim:

1. A cam device for imparting an intermittent reciprocating motion froma revolving shaft, comprising a wheel having aV tappet projecting fromits periphery and of less Width than said periphery to provide aperipheral bearing surface at the side of the tappet. and a yoke-memberhaving an elliptical-shaped recess therein to receive the wheel and bearagainst the periphery and aforesaid peripheral bearing surface withcavities in the yoke-member on a-line'with the transverse diameter ofsaid recess through which the tappet passes, and means in said cavitiesfor engagement of the tappet to move the yoke-member alternately inopposite directions upon rotation of the Wheel in either direction.

2. A cam device for imparting an intermittent reciprocating motion froma revolving shaft comprising a wheel having a tappet projecting from itsperi )hery at the center thereof to provide perip eral bearing surfacesat opposite sides of said tappet, and a yoke1nember having anellipticalshaped recess therein to receive the Wheel and bear againstthe periphery and aforesaid peripheral hearing surfaces With cavities inthe opposite Walls' of the recess on a line with the transverse diameterof the latter, and means having a limited movement in said cavities forengagement of the tappet to move the yoke-member alternately in vopposite directions upon rotation of the Wheel in either direction.

3. A cam device for imparting an intermittent reciprocating motion froma revolving shaftcomprising a Wheel having a tappet projectingtherefrom, a Vyoke member having an elliptical-shaped recess therein toreceive the Wheel upon which said yokemember is mounted to have areciprocating motion, and spring-actuated dogs in opposite Walls of therecess at opposite sides of the transverse diameter of said recess forengagement of the tappet to move the yoke member in opposite directions.

4. A camv device for operating the slidevalve of an engine, comprising awheel lsides of the transverse diameter of said recess; Whereby therotation of the Wheely causes the tappet to pass one of the shouldersand engage the companion shoulder on rotation of the Wheel in eitherdirection.

5. A cam device for operating the slidevalve of an engine to impart aquick Inoveinent thereto for the purposes set forth, comprising a wheelhaving a tappet projecting from the periphery thereof, a yoke memberhaving an internal ellipticalshaped recess by which it is mounted on thetappet-Wheel to have a reciprocating motion thereon, cavities in theopposite walls ofthe recess in the yoke member on a line with thetransverse diameter of said recess, and spring-actuated pawls in saidcavities at opposite sides of the transverse diameter of the recess,said pawls bea-ring against the ends of the cavities to provide rigidshoulders for engagement of the tappet When the tappet-Wheel 1s moved ineither direction.

